In parallel, theoretical work on the social force model [1]}, [2]}, [3]}, [4]} suggested a potential liquid-vapor transition in human movements because of social interaction [1]}, [6]}. Moreover, recent empirical studies of animals use synchronized cameras to reconstruct high-resolution moving trajectories for swarming insects [7]}, [8]}, fish [9]}, [10]}, and birds [11]}. This research indicates the coexistence of a “condensed" and a dilute “vapor" phase in equilibrium in insect swarms, calling attention to a thermodynamic description of individual movements. However, to our best knowledge, an empirical exploration of such macroscopic phases in human movement is missing in the current literature, partly due to a lack of high-resolution records of individuals’ trajectories during social events.
